How much is acceptable to spend on children at Christmas?

With Christmas looming, I've seen a lot of Facebook statuses and comments on 'mummy groups' regarding how much to spend on children at Christmas and what is acceptable. Amounts ranging from £30-£1000, there was a huge amount of variation! This got me thinking about my own budgets and spending.

Personally, I always try to buy a larger gift, lots of clothes to wear in the next size up, some books, craft items and a range of toys with topics that will interest them. I've spent around £300-£400 on each of the boys. However, my budget was lower and I've overspent a little. Although, this year, I've become a little frustrated with the volume of plastic toys in my house and invested in lots of lovely wooden toys, some costing a little more, but lovely items that the boys will treasure. 

One thing I'm passionate about is not spending money that we don't have. So, getting into debt is a no no for me personally. How much do you spend and what do you think is excessive/the right amount?